1. Field of the Invention
The present disclosure relates to an implement for use in preparing fields for planting. More particularly, it relates to an implement that cuts crop residue and mixes it with the top soil, loosens the top soil, and levels the top soil.
2. Related Art
When preparing a seedbed, it is necessary to break apart crop residue and loosen the top soil. Many implements have been devised to work the soil and prepare it to best receive seeds. For example, rotating reels slice surface material; plows, shanks, and cupped disks horizontally till the soil; and spike tooth harrows loosen the soil. Yet, each time that a tractor pulls an implement across a field, there is the possibility of compacting the soil and thereby lessening the quality of the seedbed. Moreover, each crossing of the field by a tractor represents an additional investment of labor, fuel, and machine wear, which factors into the cost of producing a commodity that is competitively priced. To minimize the steps of seedbed preparation, low-till methods have been developed which involve chopping the plant residue while disturbing only the top layer of soil. These low-till methods allow plant residue to remain largely unburied on the soil surface. When crop residue remains on the surface, the soil better retains moisture and the residue reduces erosion caused by air and water. Moreover, exposed crop residue on the surface, because it is exposed to the air, decomposes, which returns nutrients to the soil.
Recently developed crop varieties have increased resistance to attack by insects, fungi, and disease. Unfortunately, the residue from these plants also show decreased rates of degradation after harvest, which can impede subsequent plantings by clogging equipment. It has been reported that chopping the residue of resistant corn stalks and mixing them with the topsoil, which contains many of the microbes that break down dead plant material, is the best way to accelerate decomposition of plant residue prior to the next planting.
Low-till methods can require multiple tilling operations to be performed by different agricultural devices. To save time and energy, existing agricultural implements have consolidated these devices onto a single trailer that is pulled behind a tractor. For example, a single implement such as the Amco ST2 SUPER-TILL™ seedbed conditioner has two rows of live leaf or Danish shanks, followed by chopper reels, spike tooth harrows, and a choice of a drag board, double rolling baskets, or a drag pipe as a rear finishing attachment. However, the rows of shanks produce excessive horizontal tillage, contributing to undesirable soil compaction.
The McFarlane REEL SEEDBED CONDITIONER™ stalk chopper, manufactured by the McFarlane Manufacturing Co., Inc., of Sauk City, Wis., has a spiral reel, followed by a flexible spike tooth harrow, with a trailing spreader board. The McFarlane REEL TILL™ (see U.S. Pat. No. 6,698,525), also manufactured by McFarlane Manufacturing Co., has a straight coulter, a spiral reel, spike tooth harrow, and feathering board. These implements avoid horizontal tillage, and fields treated by such an apparatus tend to have well developed plant root structures. The straight coulter design causes horizontal tillage only to the extent that soil is pushed aside by the width of the straight blades. When operated in firmer soil conditions, the straight coulters of the REEL TILL™ may not create effective minimal horizontal tillage as required for optimum seedbed preparation.
Because improved seedbed conditions can result in improved yields, and hence greater profitability, there is a continuing need for a combination of field treatments that will result in optimal crop growing conditions. What is needed is a low-till agricultural implement that can prepare a superior seedbed by chopping up plant residue and controlling how much is left as ground cover, while loosening only a minimal top layer of soil and minimizing soil compaction.